A new scenario to explain the Przybylski star phenomenon is proposed. It based on supposition that this a component of binary system with neutron (similar hypothesis proposed earlier by Gopka, Ul’yanov & Andrievskii). The main difference previous as following. orbits stars lie in plane sky (or very close plane). Thus, we see (and its companion) nearly polar-on, and therefore cannot detect o...

Background: The characteristics of secondary neutrons in a high energy radiation therapy room were studied using the MCNPX Monte Carlo (MC) code. Materials and Methods: Two MC models including a model with full description of head components and a simplified model used in previous studies were implemented for MC simulations. Results: Results showed 4-53% difference between full and wit...

introduction electron linear accelerator (linac) can be used for neutron production in boron neutron capture therapy (bnct). bnct is an external radiotherapeutic method for the treatment of some cancers. in this study, varian 2300 c/d linac was simulated as an electron accelerator-based photoneutron source to provide a suitable neutron flux for bnct. materials and methods photoneutron sources w...

Introduction Electron linear accelerator (LINAC) can be used for neutron production in Boron Neutron Capture Therapy (BNCT). BNCT is an external radiotherapeutic method for the treatment of some cancers. In this study, Varian 2300 C/D LINAC was simulated as an electron accelerator-based photoneutron source to provide a suitable neutron flux for BNCT. Materials and Methods Photoneutron sources w...

These experiments compare the out-of-field dose delivered during different treatment techniques (photons, active and passive delivered protons and carbon ions) in standardized conditions. A water phantom is used as tissueequivalent material and is irradiated with a rectangular field. The dose is measured in lateral direction in the plane of the field as shown in Fig. 1. The composition of the o...

Introduction The Advanced Photon Source (APS), as well as other third-generation synchrotron light sources, uses permanent magnets in the insertion devices to produce x-rays for scientific research [1,2]. When placed in a high-energy storage ring, these permanent magnets are subjected to irradiation from synchrotron radiation, high-energy bremsstrahlung, and bremsstrahlung-produced photoneutron...

Introduction: GRID therapy is a treatment modality in which a high dose of radiation in a single fraction is given to the tumor. This technique previously was used to treat bulky tumors with orthovoltage beams. Recently, studies have been conducted to suggest that GRID therapy with megavoltage photons can be useful in palliative treatments. On the other hand, there has always ...